(a) Field of the Invention
The present invention relates to a sample applying position marking device for film for electrophoresis and, more particularly, to a sample applying position marking device to be used for marking the positions for applying the liquid samples such as blood serums onto the film for the purpose of electrophoresis.
(B) Description of the Prior Art
To analyze liquid samples such as blood serums by electrophoresis, the samples are applied onto a film such as a filter paper, cellulose acetate film or the like (hereinafter referred to as film) in straight lines and are energized through the film so that fractionated patterns of samples are formed. The film on which the fractionated patterns are formed is subjected to such processes as dyeing, decolorization, etc. and, then, subjected to colorimetric analysis by a densitometer. In the above-mentioned electrophoresis, one of known methods for applying the blood serum samples onto the film is to suck the blood serum into a micropipette and to draw a line on the film by using the micropipette. Recently, however, densitometers have been improved and automatized so that the fractionated patterns on the film are automatically analyzed in turn and recorded when the film, on which the fractionated patterns to be measured are formed, is just fed into the densitometer. When performing colorimetric analysis by such densitometer, it is necessary to apply the blood serum smaples so that the distance from the leading end of the film to the blood serum samples applied at the first position and the pitch between blood serum samples applied at respective positions become the pre-determined values which are suitable for the construction of the densitometer to be used. For this purpose, as shown in FIG. 1, marks 3 are formed on the film 1 beforehand at the positions of both ends of respective blood serum samples 2 so that the distance from the leading end of the film to the blood serum sample to be applied at the first position becomes a, the pitch between respective blood serum samples becomes p (a and p are measured by using the centers of respective blood serum samples to be applied as the standard points), and the distance from the side edge of the film to the blood serum samples in the width direction of the film becomes d. Then, the blood serum samples are applied in proper positions by utilizing those marks 3. In the known method, those marks 3 are formed by manual work. That is, a scale 4 is placed on the film 1 as shown in FIG. 2 and pinholes to be used as marks 3 are formed into the film by a needle or the like or marks 3 are formed by a pencil by reading the graduations of the scale 4. Therefore, the marking work is very inefficient.